JPH05163573A - Device and method for thin film formation - Google Patents

Abstract

PURPOSE:To uniformly form a film on a substrate in the CVD method using light. CONSTITUTION:A plasma generation chamber 4 and a reaction chamber 1 are divided by a perforated diffusion plate 12 with <=3mm diameter of through- hole and 1-5% rate of perforation where at least the surface on the reaction chamber 1 side is a diffusion one or a means for supplying gas tending to deposit to the reaction chamber is installed inside. Means for introducing gas tending to deposit are independently installed in the positions corresponding to the central part and the peripheral part of the substrate. And when a film to be formed is a SiO2 film, oxidizing gas, such as O2, O3, and N2O and silanol having at least one hydroxide group combined with a silicon atom are reacted to form the film.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film forming apparatus and a thin film forming method, and particularly to a high quality and uniform SiO ₂ film.
The present invention relates to a thin film forming apparatus and a thin film forming method capable of forming a film or a SiN film on a substrate.

[0002]

2. Description of the Related Art A thin film forming apparatus occupies an important position in the manufacturing process of semiconductor elements and electronic circuits, especially VLSI. For example, a plasma CVD apparatus is used to form a SiN film used as a final protective film, and a SiN film used for interlayer insulation.
A plasma CVD apparatus or an atmospheric pressure CV is used for forming the O ₂ film.
D apparatus is used, and sputtering apparatus is used for forming Al thin film for wiring.

When attention is paid to the SiO ₂ film for interlayer insulation, as the element is miniaturized, the SiO ₂ film for interlayer insulation is covered with a step by a SiO ₂ film formed by a plasma CVD method or an atmospheric pressure CVD method. A three-layer structure having a structure in which a spin-on-glass (SOG) having excellent properties is sandwiched is being used. However, this interlayer insulating film is apt to shrink due to post-heat treatment of SOG to easily generate cracks, and it is necessary to form the film several times in order to suppress the occurrence of cracks, resulting in a large number of steps. .. Therefore, SiO which has excellent step coverage in one step
_{As a} method for forming the ₂ film, an atmospheric pressure CV using O ₃ and tetraethyl orthosilicate (Si (OC ₂ H ₅ ) ₄ ; TEOS, also known as tetraethoxysilane) as source gases
Method D is under consideration. However, the atmospheric pressure CVD method is
Since the reaction mainly depends only on the surface reaction, the reaction is incomplete as a whole, and especially at low temperatures of 400 ° C or lower required for forming an interlayer insulating film, a large amount of hydroxyl groups and ethyl groups are mixed in the SiO ₂ film and cracks occur. It may also cause corrosion of Al wiring on this film. On the other hand, in the plasma CVD method using tetraethyl orthosilicate as a source gas, a SiO ₂ film having a better quality than that of the atmospheric pressure CVD method is formed at a low temperature of 400 ° C. or lower.

By the way, in the atmospheric pressure CVD method or the plasma CVD method, by irradiating light at the time of film formation,
It is known that the film formation reaction is accelerated. Since a thin film forming apparatus using light can be processed at low temperature and low damage in principle, its practical application is expected, and its application to cleaning and annealing is now started.

When this method using light is used to form a thin film, a window for introducing light is generally provided in the reaction vessel, but a film is formed on this window as well. It will become cloudy and the illuminance of the light entering the reaction container will be greatly reduced. Therefore, window fogging prevention methods such as a grease application method and a gas purging method have been devised. 13 and 14 are schematic cross-sectional views showing the structure of a conventional thin film forming apparatus in which fogging of a window is prevented by a grease coating method and a gas purging method, respectively.

In the thin film forming apparatus shown in FIG. 13, the cylindrical reaction container 50 has a transparent light introducing window 61 on its upper surface, and an illumination system 60 which is a surface light source is in contact with the upper side of the light introducing window 61. Is provided. An exhaust port 59 connected to an exhaust pump (not shown) is provided on the bottom surface of the reaction container 50. A support 53 is provided at a position in the reaction container 50 immediately above the exhaust port 59, and the substrate 52 to be treated is held by the support 53. The raw material gas used for the reaction is supplied into the reaction vessel 50 from a raw material gas introduction pipe 58 provided obliquely above the substrate 52. In this case, the light from the illumination system 60 is not blocked by the source gas introduction tube 58, and the base 52 is uniformly irradiated with the light.
The source gas introduction pipe 58 is provided on the side of the base 52, and the source gas is supplied from the peripheral side of the base 52.
A transparent grease is applied to the surface of the light introducing window 61 on the reaction container 50 side. In this thin film forming apparatus configured as described above, since the inorganic thin film that is usually used for semiconductor elements does not easily adhere to grease,
Formation of a film on the light introducing window 61 is suppressed, and it is possible to prevent fogging of the light introducing window 61.

The thin film forming apparatus shown in FIG. 14 is the same as the thin film forming apparatus shown in FIG. 13 except that a separating plate 62 for partitioning the reaction container 50 into upper and lower parts is provided in the center of the reaction container 50. .. The separation plate 62 is a porous plate, the space above the separation plate 62 serves as the purge chamber 54, and the space below the separation plate 62 serves as the reaction chamber 51. Therefore, the base body 52, the support body 53, and the source gas introduction pipe 5
8 and the exhaust port 59 are arranged on the reaction chamber 51 side. On the other hand, the purge chamber 54 is provided with a purge gas introduction pipe 57 for introducing a purge gas. The purge gas is a gas that is not directly involved in the reaction and is used to increase the pressure in the purge chamber 54 above the pressure in the reaction chamber 51. In this case, no grease is applied to the light introduction window 61. With this configuration, the purge chamber 54
Since the pressure is higher than that in the reaction chamber,
The light of the illumination system 60 reaches the base 52 because it does not diffuse to the 4 side and the separation plate 62 is transparent. Therefore, the film formation on the base 52 is performed while preventing the formation of the film on the light introduction window 61. You can

[0008]

In the above-described thin film forming apparatus utilizing light, the source gas is introduced from the peripheral side of the substrate so that the substrate is uniformly irradiated with light. However, there is a problem that the pressure and composition are not uniform, and the film thickness varies depending on the film forming pressure. Also,
When a grease coating method is used to prevent the formation of a film on the light introduction window, the grease component evaporated by light irradiation easily mixes into the film, and the illuminance of light is increased to improve the film formation speed. And there is a problem that the grease itself causes fogging. Even if the gas purging method is used, the purging of the raw material gas by the purging gas becomes insufficient depending on the pressure, so even if the separation plate is transparent, the film adheres and becomes cloudy, resulting in non-uniformity of the film. There is a problem of bringing.

Further, in the case of forming an SiO ₂ film for interlayer insulation, which is the largest film forming object of this type of thin film forming apparatus,
The above-mentioned tetraethyl orthosilicate is plasma CV
When the film is formed by the D method, the step coverage is not as good as that in the atmospheric pressure CVD method, and C-H is generated by ion bombardment in plasma.
There is a problem that the bond is dissociated and carbon is mixed in the film.

An object of the present invention is to solve the above-mentioned problems, to prevent fogging of the light introduction window, to provide uniform illuminance on the substrate, and to perform uniform film formation on the substrate. Another object of the present invention is to provide a thin film forming apparatus capable of performing the above, and further provide a thin film forming method capable of forming a thin film having good quality and good step coverage.

[0011]

A thin film forming apparatus according to a first aspect of the invention includes a reaction chamber, a support provided in the reaction chamber for holding a substrate, and a translucent porous diffuser plate to form a reaction chamber. A plasma generating chamber which is provided adjacently and at least partially made of a translucent member, a plasma generating means for generating plasma in the plasma generating chamber, and a first gas introducing means for introducing gas into the reaction chamber Second gas introducing means for introducing gas into the plasma generating chamber, exhaust means for exhausting the reaction chamber and the plasma generating chamber, the plasma generating chamber and the porous diffusion provided outside the plasma generating chamber A light source for irradiating light to the substrate held by the support through a plate, and at least the surface of the porous diffusion plate on the side of the reaction chamber is a diffusion surface for scattering light.

The thin film forming apparatus of the second invention comprises a reaction chamber,
A support provided in the reaction chamber for holding a substrate; a porous diffusion plate that is transparent and has at least one surface that is a diffusion surface that scatters light and that is provided with a plurality of through holes; A purge chamber which is provided adjacent to the reaction chamber via a plate and at least a part of which is a translucent member; and a first purge chamber which is provided in the porous diffusion plate and introduces a deposition gas into the reaction chamber. Gas introducing means, second gas introducing means for introducing a non-depositing gas into the purge chamber, exhaust means for exhausting the reaction chamber and the purge chamber, and the purge chamber provided outside the purge chamber And a light source for irradiating the substrate held by the support with light through the porous diffusion plate.

The thin film forming apparatus of the third invention comprises a reaction chamber,
A support provided in the reaction chamber for holding a substrate; a porous diffusion plate that is transparent and has at least one surface that is a diffusion surface that scatters light and that is provided with a plurality of through holes; A plasma generation chamber which is provided adjacent to the reaction chamber via a plate and at least a part of which is made of a translucent member;
Plasma generating means for generating plasma in the plasma generating chamber, first gas introducing means provided in the porous diffusion plate for introducing a depositing gas into the reaction chamber, and non-depositing in the plasma generating chamber Second gas introducing means for introducing gas, exhaust means for exhausting the reaction chamber and the plasma generating chamber, and the support provided outside the plasma generating chamber via the plasma generating chamber and the porous diffusion plate. And a light source for irradiating the base body held by the body with light.

In the thin film forming apparatus of the fourth invention, a reaction chamber at least a part of which is made of a translucent member, a support provided in the reaction chamber for holding a substrate, and a center of the substrate in the reaction chamber. A first gas introducing means for introducing a deposition gas to a position corresponding to the portion, and the first gas introducing means is provided independently of the first gas introducing means at the position corresponding to the peripheral portion of the substrate in the reaction chamber. A second gas introducing unit for introducing a reactive gas, an exhaust unit for evacuating the reaction chamber, and a light source for irradiating the substrate, which is provided outside the reaction chamber and held by the support, with light.

The thin film forming apparatus of the fifth invention comprises a reaction chamber,
A support provided in the reaction chamber for holding a substrate, a translucent porous diffusion plate having a plurality of through holes, and at least a part provided adjacent to the reaction chamber via the porous diffusion plate. A plasma generating chamber consisting of a translucent member, plasma generating means for generating plasma in the plasma generating chamber, and introducing a depositive gas into the reaction chamber at a position corresponding to the center of the substrate. And a second gas introducing unit which is provided independently of the first gas introducing unit and which introduces the sedimentary gas into a position corresponding to the peripheral portion of the substrate in the reaction chamber, Third gas introducing means for introducing a non-depositing gas into the plasma generating chamber, exhaust means for exhausting the reaction chamber and the plasma generating chamber, the plasma generating chamber and the outside of the plasma generating chamber Many The retained substrate to the support through a diffusion plate and a light source for irradiating light.

According to the thin film forming method of the sixth invention, S is formed on the substrate.
A thin film forming method for forming an iO ₂ film, comprising: reacting an oxidizing gas excited by plasma with silanol having at least one hydroxyl group bonded to a silicon atom to deposit a SiO ₂ film on the substrate. It has a reaction step.

[0017]

In the first aspect of the invention, as the separating plate in the above-mentioned conventional gas purging method, the porous diffusing plate which is transparent and at least the reaction chamber side surface is a diffusing surface for scattering light is used. The incident light is diffused by this porous diffusion plate, and the uniformity of illuminance on the substrate is improved. Further, the porous diffusion plate causes a pressure difference between the plasma generation chamber and the reaction chamber, and the deposition gas (raw material gas) supplied to the reaction chamber side is almost completely prevented from diffusing to the plasma generation chamber side. Be done. Therefore, the adhesion of the film to the light incident window or the like can be suppressed. Further, even if a film adheres to the porous diffusion plate and light scattering is newly generated due to the unevenness of the film, the incident light is scattered by the diffusion surface in advance, so that the change in illuminance on the substrate is reduced. ..

When the diameter of the through-hole provided in the diffusion perforated plate is large, a shadow of the through-hole is formed on the substrate and the uniformity of illuminance is deteriorated. Therefore, the hole diameter should be about 3 mm or less. If the opening ratio of the through holes to the entire porous diffusion plate exceeds 5%, a sufficient pressure difference cannot be established between the plasma generation chamber and the reaction chamber, and the gas diffusion from the reaction chamber side is impossible. It cannot be ignored, and it becomes impossible to effectively prevent the film from adhering to the light incident window. On the other hand, when the aperture ratio is less than 1%, the pressure inside the plasma generation chamber rises too much, and it becomes difficult to generate plasma. Therefore, the aperture ratio should be about 1-5%. As a method of generating plasma in the plasma generation chamber, there is a known method of introducing high frequency power or microwave power into the plasma generation chamber. At this time, in order to efficiently introduce these energies into the plasma generation chamber, it is preferable that the plasma generation chamber has a cylindrical shape and the side wall be made of a quartz tube. In the second and third inventions, a first gas introducing means provided in the porous diffusion plate for introducing a deposition gas into the reaction chamber, and a non-deposition gas introducing into the purge chamber or the plasma generation chamber Since the second gas introduction means is provided, eventually, both the deposition gas and the non-deposition gas flow uniformly from the porous diffusion plate to the substrate, and it is possible to uniformly form a film on the substrate. Become. As such a porous diffusion plate, for example, two transparent plates arranged at intervals are used, and a large number of holes are formed in the lower plate so that a sedimentary gas flows between the two plates. This is achieved by providing a first gas introducing means, and further providing a tubular through hole that connects the upper plate and the lower plate. In this case, since the through hole is tubular, the non-depositing gas from the plasma generating chamber or the purging chamber does not enter between the two porous diffusion plates. Either through-holes for non-depositing gas or holes drilled in the lower plate for depositing gas,
The diameter is preferably 3 mm or less. Further, in order to allow the deposition gas to flow uniformly, it is desirable that the cross-sectional area of the portion of the porous diffusion plate sandwiched between the two plates be sufficiently larger than the area of the holes formed in the lower plate. ..

In the fourth and fifth inventions, the first aspect of introducing the deposition gas into the reaction chamber at a position corresponding to the central portion of the substrate.
And the second gas introducing means for introducing the sedimentary gas into a position corresponding to the peripheral portion of the substrate in the reaction chamber, which is provided independently of the first gas introducing means. The amount of the deposition gas supplied to the peripheral part and the central part can be controlled independently, and the film thickness in the central part, which was apt to be insufficient in the conventional device, can be compensated for, and uniform film formation is possible. Become.
In this case, it is desirable that the first gas introduction tube is formed of a transparent thin tube having a through hole in the wall surface so as not to form a shadow on the substrate, and also to prevent light from being condensed. Therefore, it is desirable that the cross section be rectangular.

In the above first to fifth inventions, the deposition gas directly supplied to the reaction chamber is, for example, S
Organic silane compounds such as iH ₄ , Si ₂ H ₆ , SiCl ₂ H ₂ , alkoxysilane, siloxane, silanol, etc., organic compounds such as diborane, arsine, phosphine, alkanes, alkenes, alkynes, alcohols, benzene, organic aluminum compounds, organic Titanium compounds, WF ₆ , organic tungsten compounds, organic molybdenum compounds, organic tantalum compounds, and the like. On the other hand, as the non-depositing gas supplied to the purge chamber and the plasma generation chamber, O ₂ , O ₃ , N ₂ O,
_{H 2 O, N 2, NH} 3, N 2 H 4, H 2, Ar , and the like.

In the sixth aspect of the invention, the oxidizing gas excited by the plasma and at least 1 bonded to the silicon atom are used.
Since the SiO ₂ film is deposited and formed on the substrate by reacting with silanol having one hydroxyl group, interaction with the substrate surface is reduced, surface diffusion is promoted, and a SiO ₂ film with improved step coverage is obtained. Be done. Further, since it is silanol, it mainly contains a hydroxyl group, so that carbon contamination in the film is reduced. By irradiating the substrate with ultraviolet light or visible light during film formation, the incorporation of hydroxyl groups is reduced and the film quality is further improved.

Examples of the oxidizing gas used in the present invention include O ₂ , O ₃ and N ₂ O. The silanol may be an organic silanol containing an alkyl group or the like, or an inorganic silanol containing no alkyl group, etc., but those having a high saturated vapor pressure and a low carbon content are preferable. Since the silanol increases its supply amount, it may be produced by the reaction of the organic silane or the inorganic silane with water immediately before the deposition on the substrate. The plasma used to excite the oxidizing gas may be generated by a high frequency wave of about 1 to 300 MHz or may be generated by a microwave wave of about 0.9 to 5 GHz. Further, in order to improve the electron density, a magnetic field may be applied during plasma generation.

[0023]

Embodiments of the present invention will now be described with reference to the drawings.

[Embodiment 1] FIG. 1 is a schematic sectional view showing the structure of a thin film forming apparatus in Embodiment 1 of the present invention. This thin film forming apparatus corresponds to the above-mentioned first invention, and uses a porous diffusion plate in which at least the surface on the reaction chamber side is a diffusion surface that scatters light.

An exhaust port 9 connected to an exhaust pump (not shown) via a conductance valve (not shown) is provided on the bottom surface of the cylindrical reaction chamber 1, and the support member 3 is provided directly above the exhaust port 9. Is provided. The support 3 is
This is for holding the substrate 2 to be processed, that is, the film formation target on the upper surface thereof. Further, inside the reaction chamber 1, a raw material gas introduction pipe 8 for introducing a deposition gas is provided in the base body 2.
It is provided so as to be positioned obliquely above and close to the base body 2 so that it does not come directly above. The source gas introduction pipe 8 is connected to a source gas supply source (not shown). The upper surface of the reaction chamber 1 is the porous diffusion plate 12, and the porous diffusion plate 12 also serves as the bottom surface of the cylindrical plasma generation chamber 4. That is, the plasma generation chamber 4 and the reaction chamber 1 are adjacent to each other and connected to each other via the porous diffusion plate 12. The porous diffusion plate 12 made of a transparent material such as fused quartz is provided with a large number of through holes having a diameter of 3 mm or less so that the aperture ratio is 1 to 5%. Also,
The surface of the porous diffusion plate 12 on the side of the reaction chamber 1 is subjected to frosted glass treatment to be a diffusion surface for light.

The side wall of the plasma generating chamber 4 is composed of a quartz tube 5, and an electrode 6 for generating a high frequency or microwave plasma discharge in the plasma generating chamber 4 is attached to the outside of the quartz tube 5. The electrode 6 is connected to a high frequency power source or a microwave power source (not shown). Inside the plasma generating chamber 4, a non-depositing gas introducing pipe 7 for introducing a non-depositing gas used for generating plasma into the plasma generating chamber 4 is provided along the inner surface of the quartz pipe 5. Are provided. The non-depositing gas introduction pipe 7 is connected to a non-depositing gas supply source (not shown). A transparent light introduction window 11 is provided on the upper surface of the plasma generation chamber 4, and an illumination system 10 which is a light source is provided above and adjacent to the light introduction window 11.

Next, the operation of this thin film forming apparatus will be described.

First, the substrate 2 is held on the support 3, and the reaction chamber 1 and the plasma generation chamber 4 are evacuated. Since the porous diffusion plate 12 is provided with a large number of through holes, by exhausting from the exhaust port 9 provided on the reaction chamber 1 side, not only the reaction chamber 1 but also the plasma generation chamber 4 is exhausted. Become. When the vacuum is exhausted to a predetermined vacuum level, the illumination system 10 is activated. Light from the illumination system 10 passes through the light introduction window 11 and the porous diffusion plate 12 and enters the surface of the base 2. At the same time, a gas for plasma generation is introduced into the plasma generation chamber 4 from the non-depositing gas introduction pipe 7, and a deposition gas which is a raw material gas is introduced into the reaction chamber 1 from the raw material gas introduction pipe 8. Further, high frequency power is applied to the electrode 6. At this time, the reaction chamber 1
Since the gas is exhausted from the side, the pressure in the plasma generation chamber 4 becomes higher than that in the reaction chamber 1.

As a result, plasma discharge occurs in the plasma generation chamber 4, and the non-depositing gas is excited by plasma,
The excited gas passes through the porous diffusion plate 12 and moves into the reaction chamber 1. In the reaction chamber 1, the excited gas reacts with the deposition gas to form a film on the substrate 2. At this time, since the porous diffusion plate 12 whose surface on the reaction chamber 1 side is a diffusion surface that scatters light is used, the light from the illumination system 10 is diffused by this porous diffusion plate, and the illuminance on the substrate 2 is increased. It becomes uniform, and the film is uniformly formed on the substrate 2. Moreover, since the pressure in the plasma generation chamber 4 is higher than that in the reaction chamber 1, the deposition gas does not diffuse to the plasma generation chamber 4 side. Therefore, in the plasma generation chamber 4 such as the light entrance window 11, The adhesion of the film is suppressed. Porous diffusion plate 12
Although the film adheres to the upper part to some extent, the light from the illumination system 10 is scattered by the diffusing surface in advance even if the scattering of the light newly occurs due to the unevenness of the adhered film. There is little change in illuminance.

When the film having the predetermined thickness is completed, the application of the high frequency or microwave power to the electrode 6 is stopped, the introduction of the depositing gas and the non-depositing gas is stopped, and the film-formed substrate 2 is formed. Just take out.

[Embodiment 2] This is an example of forming a SiO ₂ film on the substrate 2 by utilizing high frequency for plasma generation in the above Embodiment 1. FIG. 2 is a schematic cross-sectional view showing the structure of the thin film forming apparatus used in the second embodiment.

In this thin film forming apparatus, in addition to the one shown in the first embodiment, in order to generate a plasma by applying a magnetic field perpendicular to the electric field, the magnet 13 has its magnetic pole axis oriented vertically inside the electrode 6. Is provided. The electrode 6 is connected to the high frequency power supply 25. As the illumination system 10, a system including a xenon lamp that emits a parallel light flux and an integrator was used. As the porous diffusion plate 12, a fused silica plate having a through hole diameter of 2 mm, an opening ratio of 2%, and a surface on the reaction chamber 1 side that was frosted with a roughness of 0.2 mm was used. When a substrate having a diameter of 150 mm was used, the illuminance variation on this substrate 2 was ± 2%.
Met. This variation in illuminance is improved compared to the variation value of ± 5% when the conventional porous transparent flat plate having no diffusion surface is used.

O ₂ gas ₂ slm as non-depositing gas
(However, 1 slm = 1000 sccm) is supplied into the plasma generation chamber 4, tetraethyl orthosilicate 200 sccm as a deposition gas is supplied into the reaction chamber 1, and high-frequency power of 1 kW is applied to the electrode 6 to generate plasma to generate plasma. The film was formed, and the film was formed 100 times for 2 minutes each. After that, the transmittance of the light introducing window 11 was measured. In addition, the porous diffusion plate 1
The vertical transmittance at a distance of 50 mm from the center of 2 is 6
The value was 1%, and the change from the value before film formation of 64% was small.

On the other hand, when a conventional porous transparent flat plate having no diffusing surface is used instead of the porous diffusion plate 12, the transmittance 89% before film formation is lowered to 63% after film formation, and It was found that the change in illuminance above was large. That is, when the porous diffusion plate 12 of the present example is used, the absolute illuminance is reduced, but the uniformity of the illuminance is improved and the illuminance before and after film formation is improved compared with the case where the conventional porous transparent flat plate is used. It was found that there were few changes and that it was practically excellent.

[Third Embodiment] Next, a third embodiment of the present invention will be described. This embodiment corresponds to the second invention. FIG. 3 is a schematic cross-sectional view showing the structure of the thin film forming apparatus in this Embodiment 3, FIG. 4 is a partial plan view of a porous diffusion plate,
FIG. 5 is a partial cross-sectional view taken along the line AA ′ of FIG.

This thin film forming apparatus is the same as that shown in the first embodiment, but the deposition gas is added to the porous diffusion plate 1.
5 is different from that of Example 1 in that it is introduced into the reaction chamber 1 through the inside of No. 5 and that plasma discharge is not used. Therefore, a source gas introduction pipe is not provided inside the reaction chamber 1, and a cylindrical purge chamber 14 is provided instead of the plasma generation chamber. Similar to the plasma generation chamber 4 (FIG. 1) of the first embodiment, this purge chamber 14 has a porous diffuser plate 15 on the bottom surface and the light introduction window 11 on the upper surface.
In addition, the non-depositing gas introduction pipe 7 is provided inside. It is also the same that the illumination system 10 is provided close to the light introduction window 11. A non-depositing gas such as a so-called purge gas is introduced into the purge chamber 14 from the non-depositing gas introducing pipe 7. further,
A heater 20 for heating the substrate 2 is attached to the support 3 in the reaction chamber 1.

The details of the porous diffusion plate 15 used in this embodiment will be described below. This porous diffusion plate 15 is
As shown in FIGS. 4 and 5, it is composed of two light-transmissive plates 18 and 19 which are arranged at intervals and allow light to pass therethrough. A large number of ejection holes 1 are formed in the translucent plate 18 on the lower side, that is, the reaction chamber 1 side.
7 is provided so that the deposition gas flowing between the two translucent plates 18 and 19 is supplied to the reaction chamber 1 through the ejection holes 17. Further, the upper transparent plate 19
A tubular through hole 16 is provided to connect the transparent plate 18 and the lower transparent plate 18 to each other. Since the through hole 16 has a tubular shape, the non-depositing gas from the purge chamber 14 has two translucent plates 18 and 1.
It is designed not to enter the space between the nine.
The inner diameter of each of the through hole 16 and the ejection hole 17 is 3 mm or less. The space between the two light-transmitting plates 18 and 19 is connected to a supply source (not shown) of the deposition gas, and the lower light-transmitting plate 18 has the above-mentioned embodiment. The same frosted glass treatment as in No. 1 is applied.

Using this thin film forming apparatus, a silicon substrate was used as the substrate 2, and a SiN film for a protective film was formed on the substrate 2 by the photo-CVD method. First, the base 2 and the support 3
After holding it above and evacuating the reaction chamber 1 and the purge chamber 14 to a predetermined vacuum degree, the substrate 2 was heated by the heater 20 from room temperature to a desired temperature of several hundreds of degrees Celsius. Then, NH ₃ gas is supplied to the purge chamber 14 from the non-depositing gas introduction pipe 7, and SiH ₄ gas is supplied from the ejection holes 17 of the porous diffusion plate 15 to the reaction chamber 1.
The inside of the reaction chamber 1 was maintained at a desired pressure of 1 to 20 Torr by adjusting a conductance valve (not shown) connected to the exhaust port 9 and supplied to the inside. Then, the light from the illumination system 10
The substrate 2 is irradiated with light through the light introducing window 11 and the porous diffusion plate 15.

As a result, NH ₃ gas from the through hole 16
Further, SiH ₄ gas uniformly flows from the ejection holes 17 toward the substrate 2, and when film formation is performed until a desired film thickness is obtained, a high-quality SiN film is formed on the substrate 2.
The film was formed uniformly.

By changing the gas supplied to the reaction chamber 1 and the purge chamber 14, SiN, SiO ₂ , Ta ₂ O ₅ , Al ₂
Insulators such as O ₃ and AlN, amorphous Si, polycrystalline Si, Ga
It is possible to deposit a semiconductor such as As or a metal such as Al or W.

[Fourth Embodiment] Next, a fourth embodiment of the present invention will be described. This embodiment corresponds to the third invention. FIG. 6 is a schematic cross-sectional view showing the structure of the thin film forming apparatus according to the fourth embodiment.

This thin film forming apparatus is the same as that shown in the first embodiment, but the deposition gas is added to the porous diffusion plate 1.
Example 1 in that it is introduced into the reaction chamber 1 through the inside of
Is different from the one. Therefore, the source gas introduction pipe is not provided inside the reaction chamber 1, and the porous diffusion plate 15
The same as that used in the above-mentioned third embodiment is used as. Further, in order to generate a plasma by applying a magnetic field perpendicular to the electric field, a magnet 13 is provided inside the electrode 6 such that its magnetic pole axis is oriented vertically. The electrode 6 is connected to a high frequency power source (not shown). Further, a heater 20 for heating the substrate 2 is attached to the support 3 in the reaction chamber 1.

Using this thin film forming apparatus, a silicon substrate was used as the substrate 2, and an SiO ₂ film for interlayer insulation was formed on the substrate 2 by the photo-assisted plasma CVD method.
First, the base 2 is held on the support 3, and the light from the illumination system 10 passes through the light introduction window 11 and the porous diffuser plate 15 and the base 2
It was made to irradiate on. After evacuating the reaction chamber 1 and the plasma generation chamber 4 to a predetermined degree of vacuum, the substrate 2 was heated by the heater 20 from room temperature to a desired temperature of several hundreds of degrees Celsius.
Subsequently, O ₂ gas was supplied to the plasma generation chamber 4 from the non-depositing gas introduction pipe 7, and tetraethyl orthosilicate was supplied to the reaction chamber 1 from the ejection holes 17 of the porous diffusion plate 15, and was connected to the exhaust port 9. A conductance valve (not shown) was adjusted to maintain the reaction chamber at a desired pressure of 0.1 to 0.5 Torr. Then, high frequency power was supplied to the electrode 6.

As a result, since the electrode 13 is provided with the magnet 13, a plasma localized in the vicinity of the electrode 6 is generated in the plasma generation chamber 4, and O ₂ gas is excited and excited. Further, the O ₂ gas and the tetraethyl orthosilicate will flow evenly toward the substrate 2 from the through holes 16 and the ejection holes 17, respectively. When film formation was performed until a desired film thickness was obtained, a good quality Si was formed on the substrate 2.
The O ₂ film was uniformly formed. By changing the gas supplied to the reaction chamber 1 and the plasma generation chamber 4, SiN, S
It is possible to form an insulator such as iO ₂ , Ta ₂ O ₅ , Al ₂ O ₃ or AlN, a semiconductor such as amorphous Si, polycrystalline Si or GaAs, or a metal such as Al or W.

[Embodiment 5] Next, Embodiment 5 of the present invention will be described. This embodiment corresponds to the fourth invention. FIG. 7 is a schematic cross-sectional view showing the structure of the thin film forming apparatus according to the fifth embodiment.

This thin film forming apparatus is based on the photo-CVD method, and comprises a cylindrical reaction vessel 21. The bottom surface of this reaction vessel 21 is the exhaust port 9 as in the above-mentioned embodiments.
And a support 3 for holding the base body 2. A heater 20 for heating the base body 2 is attached to the support body 3. On the other hand, the reaction container 2
The upper surface of 1 is a light introduction window 11, and an illumination system 10 is provided near the light introduction window 11.

A first gas introduction pipe 22 made of a transparent thin tube is provided at a position directly above the substrate 2 of the reaction vessel 21. The first gas introduction pipe 22 has a rectangular cross section, and a large number of ejection holes are provided on the surface facing the base body 2 (the lower surface in the drawing). In addition, the second gas introduction pipe 23
Is provided in the reaction container 21 so as to be positioned obliquely above the substrate 2 so as not to be directly above the substrate 2. The second gas introduction pipe 23 is provided with ejection holes on its side surface so as to face the base 2. Although these first and second gas introduction pipes 22 and 23 are for supplying the same source gas into the reaction vessel 21, their flow rates can be independently controlled. Further, a third gas introduction pipe 24 is provided near the light introduction window 11. This third gas introduction pipe 24 is connected to the first and second
Gas different from the gas introduction pipes 22 and 23 of the reaction vessel 21
It is for supplying inside. In this case, since the first gas introduction pipe 22 provided above the base 2 is transparent, the shadow of the first gas introduction pipe 22 does not occur on the base 2, and the first gas introduction pipe 22 does not have a shadow. Since the cross section is rectangular, the light from the illumination system 11 will not be unintentionally collected. Therefore, the unevenness of the illuminance on the substrate 2 due to the provision of the first gas introduction pipe 22 does not occur.

Using this thin film forming apparatus, a silicon substrate was used as the substrate 2, and a SiO ₂ film was formed on the substrate 2. First, the substrate 2 is held on the support 3 and the reaction container 21
After the inside is evacuated to a predetermined degree of vacuum, the base 2 is heated by the heater 20.
Was heated from room temperature to the desired temperature of several hundred ° C. SiH ₄ gas is supplied into the reaction vessel 21 from the first and second gas introduction pipes 22 and 23, and N ₂ O is supplied from the third gas introduction pipe 24.
Gas is supplied into the reaction container 21, and a conductance valve (not shown) connected to the exhaust port 9 is adjusted to adjust the reaction container 2
The inside of 1 was maintained at the desired pressure of 1 to 20 Torr. And
Light from the illumination system 10 passes through the light introduction window 11 and the substrate 2
It was made to irradiate on. At this time, the flow rates of the first gas introduction pipe 22 and the second gas introduction pipe 23 were respectively controlled so that the SiH ₄ gas was uniformly supplied onto the substrate 2.

As a result, the raw material gas is evenly supplied onto the substrate 2 and the illuminance on the substrate 2 is also uniform, so that a high-quality Si is obtained.
The O ₂ film was uniformly formed.

The gas supplied to the reaction vessel 21 can be changed.
With, SiN, SiO₂, Ta₂O _Five, Al₂O₃, AlN
Insulators such as, amorphous Si, polycrystalline Si, GaAs, etc.
It is possible to deposit a metal such as a semiconductor or Al or W.

[Sixth Embodiment] Next, a sixth embodiment of the present invention will be described. This embodiment corresponds to the fifth invention. FIG. 8 is a schematic cross-sectional view showing the structure of the thin film forming apparatus according to the sixth embodiment, and FIG. 9 shows the central portion and the peripheral portion of the substrate 2 when a SiO ₂ film is deposited using this thin film forming apparatus. It is a characteristic view which shows the relationship between the film-forming speed and the pressure in the reaction chamber 1.

This thin film forming apparatus is the same as that shown in Example 1, except that the source gas introduction pipe is used instead of the source gas introducing pipe.
The reaction chamber 1 is provided with the first and second gas introduction pipes 22 and 23 of the fifth embodiment. Further, in order to generate a plasma by applying a magnetic field perpendicular to the electric field, a magnet 13 is provided inside the electrode 6 such that its magnetic pole axis is oriented vertically. The electrode 6 is connected to a high frequency power source (not shown). Further, the support 3 in the reaction chamber 1
A heater 20 for heating the substrate 2 is attached to the. The diameter of the through holes and the aperture ratio in the porous diffusion plate 12 are not limited to the ranges in the first embodiment.

Using this thin film forming apparatus, a silicon substrate was used as the substrate 2, and an SiO ₂ film for interlayer insulation was formed on the substrate 2 by the photo-assisted plasma CVD method.
First, the base 2 is held on the support 3, and the light from the illumination system 10 passes through the light introduction window 11 and the porous diffuser plate 15 and the base 2
It was made to irradiate on. After evacuating the reaction chamber 1 and the plasma generation chamber 4 to a predetermined degree of vacuum, the substrate 2 was heated by the heater 20 from room temperature to a desired temperature of several hundreds of degrees Celsius.
Then, O ₂ gas is supplied to the plasma generation chamber 4 from the non-depositing gas introducing pipe 7, and the first and second gas introducing pipes 22,
Tetraethyl orthosilicate was supplied from 23 to the reaction chamber 1, and a conductance valve (not shown) connected to the exhaust port 9 was adjusted to maintain the reaction chamber at a desired pressure of 0.1 to 0.5 Torr. At this time, the flow rates of the first gas introduction pipe 22 and the second gas introduction pipe 23 are controlled,
The tetraethyl orthosilicate gas was evenly supplied onto the substrate 2. Then, high frequency power was supplied to the electrode 6.

As a result, since the electrode 13 is provided with the magnet 13, a plasma localized in the vicinity of the electrode 6 is generated in the plasma generation chamber 4, and O ₂ gas is excited and excited. The O ₂ gas passes through the porous diffusion plate 12 and the reaction chamber 1
Will be supplied to. In the reaction chamber 1, the O ₂ gas excited in the presence of light from the illumination system 10 reacts with tetraethyl orthosilicate to form a SiO ₂ film on the substrate 2, but on the substrate 2. Since the illuminance and the supply of the tetraethyl orthosilicate gas to the substrate 2 are uniform, when film formation was performed until a desired film thickness was obtained,
A good quality SiO ₂ film was uniformly formed on the substrate 2.

Here, when the relationship between the pressure in the reaction chamber 1 and the film forming rates at the central portion and the peripheral portion of the substrate 2 was examined, it was as shown in FIG. 9, and the pressure as a whole was found. Although the film forming rate also increased with increasing, the difference in film forming rate between the central portion and the peripheral portion of the substrate 2 was almost zero.

By changing the gas supplied to the reaction chamber 1 and the plasma generation chamber 4, SiN, SiO ₂ , Ta ₂ O ₅ , A
Insulators such as l ₂ O ₃ and AlN, amorphous Si, polycrystalline Si,
It is possible to deposit a semiconductor such as GaAs or a metal such as Al or W.

Comparative Example 1 Using the thin film forming apparatus of Example 6 described above, tetraethylorthosilicate was supplied to the reaction chamber 1 only from the second gas introducing pipe 23, that is, the peripheral portion of the substrate 2, and the others were used. Film formation was performed under the same conditions as in Example 6. When the relationship between the pressure in the reaction chamber 1 and the film forming rates at the central portion and the peripheral portion of the substrate 2 at this time was examined, it was as shown in FIG. There was almost no difference in the film forming rate in the area when the pressure was 0.2 Torr or less, and the difference began to widen as the pressure exceeded 0.2 Torr, and the difference was doubled at 0.5 Torr.

Comparative Example 2 Using the thin film forming apparatus of Example 6 described above, the tetraethyl orthosilicate is supplied to the reaction chamber 1 only from the first gas introduction pipe 23, that is, the one corresponding to the central portion of the substrate 2. The film formation was performed under the same conditions as in Example 6 except for the above. When the relationship between the pressure in the reaction chamber 1 and the film forming rates at the central portion and the peripheral portion of the substrate 2 at this time was examined, it was as shown in FIG. The film forming speed in the part is 0.
At 2 Torr or less, there is almost no difference, and when it exceeds 0.2 Torr, the difference widens, and at 0.5 Torr, the difference is about 2.5 times.

From Examples 5 and 6 and Comparative Examples 1 and 2 described above, it is effective to introduce the source gas corresponding to each of the peripheral portion and the central portion of the substrate to achieve uniform film formation. I understood it.

[Seventh Embodiment] Next, a seventh embodiment of the present invention will be described. This embodiment is SiO 2 according to the sixth invention.
It is intended to form _two films. FIG. 12 is a schematic cross-sectional view showing an example of the configuration of a thin film forming apparatus used for carrying out the seventh embodiment.

This thin film forming apparatus is based on the plasma CVD method. An exhaust port 39 connected to an exhaust pump (not shown) via a conductance valve (not shown) is provided on the bottom surface of the cylindrical reaction container 31 that can be exhausted. The support 33 is provided at a position directly above the exhaust port 39.
Is provided. The support 33 is for holding the substrate 32 to be processed, that is, the film formation target on the upper surface thereof. Further, inside the reaction vessel 31, a silanol gas introduction pipe 38 for introducing the silanol having at least one hydroxyl group bonded to a silicon atom into the reaction vessel 31 is provided close to the base body 32. .. The silanol gas introducing pipe 38 is arranged obliquely above the base 32 so that it does not come directly above the base 32, and the reaction container 3
1 is connected to a silanol generator (not shown) provided adjacent to the outside. The silanol generation device is, for example, a device that generates silanol by the reaction of tetraethyl orthosilicate and water, and the generated silanol immediately passes through the silanol gas introduction pipe 38 and the reaction container 3
1 is supplied. In addition, the reaction container 31
Oxidizing gas such as O ₂ is placed near the top plate of the reaction vessel 3
An oxidative gas supply pipe 37 for supplying the gas to the fuel cell 8 is provided. The oxidizing gas supply pipe 37 is connected to a supply source (not shown).

The upper half of the side wall of the cylindrical reaction vessel 38 is composed of a quartz tube 35 for introducing high frequency power into the reaction vessel 31, and the reaction vessel 31 is provided outside the quartz tube 35.
An electrode 36 for generating a high frequency discharge is attached inside, and in order to generate a plasma by applying a magnetic field perpendicular to an electric field, a magnet 43 is provided inside the electrode 36 so that its magnetic pole axis faces up and down. ing. The electrode 36 is connected to the high frequency power supply 45.

Next, a method of forming a SiO ₂ film by this thin film forming apparatus will be described.

First, the base 32 is placed on the support 33,
After exhausting the inside of the reaction container 31, the base 32 is heated from room temperature to a desired temperature of several hundreds of degrees Celsius by a heating means (not shown). Next, oxidizing gas and silanol are supplied into the reaction vessel 31 through the oxidizing gas introducing pipe 37 and the silanol gas introducing pipe 38, respectively, and a conductance valve (not shown) connected to the exhaust port 39 is adjusted. Then, the inside of the reaction vessel 31 is maintained at a desired pressure of 0.05 to 1.0 Torr. further,
In the presence of a magnetic field of about several hundred G generated by the magnet 43, a high frequency power of about 100 to 1,000 W is applied to the electrode 36 to generate plasma near the electrode 36 in the reaction vessel 31,
Exciting oxidizing gas. As a result, the excited oxidizing gas reacts with silanol to form a SiO ₂ film on the substrate 32. After forming the film to a desired thickness, the substrate 32 after the film formation may be taken out from the reaction container 31.

Now, the result of actual film formation using this thin film forming apparatus will be described. O ₂ gas was ₂ slm as the oxidizing gas, silanol was used as the silanol, and 400 sccm of the silanol produced immediately by the reaction of tetraethyl orthosilicate and water was supplied to the reaction vessel 31, and the pressure in the reaction vessel 31 was set to 0.2 Torr, Base 32
The temperature was 300 ° C., the high frequency power applied to the electrode 36 was 500 W, and the magnetic flux density generated by the magnet 43 was 150 G. As a result, there are few hydroxyl groups and carbon,
A SiO ₂ film having good coverage was formed on the substrate 32.

[Embodiment 8] Next, an embodiment 8 of the invention will be described. In this example, the thin film forming method of the sixth invention is carried out by the photo-assisted plasma CVD method using the same thin film forming apparatus as in Example 2, and SiO for interlayer insulation is used.
_It forms _two films.

The thin film formation in this embodiment will be described.
A thin film forming apparatus similar to that used in Example 2 (FIG. 2) was used, but a porous diffusion plate having at least one surface as a diffusion surface was used. In this case, regarding the diameter and the opening ratio of the through hole of the porous diffusion plate,
It is not limited to the range in.

First, the substrate 2 is placed on the support 3, and the reaction chamber 1 and the plasma generation chamber 4 are evacuated. The substrate 2 is heated from room temperature to a desired temperature of several hundreds of degrees Celsius by a heating means (not shown), and the light from the illumination system 10 using a xenon lamp as a light source is transmitted through the light introduction window 11 and the porous diffusion plate 12 to thereby form the substrate 2. To irradiate. Next, the non-depositing gas introduction pipe 7
From the raw material gas introduction pipe 8 to the reaction chamber 1 and the silanol having at least one hydroxyl group bonded to a silicon atom, and the conductance valve connected to the exhaust port 9 ( The inside of the reaction chamber 1 is maintained at a desired pressure of 0.05 to 1.0 Torr (not shown). Further, in the presence of a magnetic field of about several hundred G generated by the magnet 13, high frequency power of about 100 to 1,000 W is applied to the electrode 6 to generate plasma in the vicinity of the electrode 6 in the plasma generation chamber 4 for oxidation. Exciting a sexual gas. As a result, the excited oxidizing gas moves to the reaction chamber 1 and reacts with silanol to form a SiO ₂ film on the substrate 2. After forming the film to a desired thickness, the substrate 2 after the film formation may be taken out.

Here, the result of actual film formation using this thin film forming apparatus will be described. O ₂ gas of 1.5 slm was supplied to the plasma generation chamber 4 as an oxidizing gas, and 400 sccm of silanol produced by reacting silane and water immediately before was supplied to the reaction chamber 1 as silanol, and the pressure in the reaction chamber 1 was adjusted. 0.1 Torr, the temperature of the substrate 2 is 300 ° C.,
Film formation was performed with the high frequency power applied to the electrode 6 set to 400 W and the magnetic flux density generated by the magnet 13 set to 150 G. As a result, an SiO ₂ film having a small amount of impurities such as hydroxyl groups, especially carbon, and good coverage was formed on the substrate 2.

[0070]

As described above, the thin film forming apparatus of the present invention uses the porous diffusion plate which is transparent and has at least the reaction chamber side surface as a diffusion surface for scattering light.
Providing a first gas introduction unit provided in the porous diffusion plate for introducing a deposition gas into the reaction chamber and a second gas introduction unit introducing a non-deposition gas into the purge chamber or the plasma generation chamber. Alternatively, the first gas introducing means for introducing the deposition gas into a position corresponding to the central portion of the substrate in the reaction chamber, and the first gas introducing means are provided independently of each other, and the peripheral portion of the substrate in the reaction chamber is provided. By providing the second gas introduction means for introducing the deposition gas to the position corresponding to the above, the illuminance of the light irradiating the substrate, the flow and amount of the gas supplied to the substrate become uniform, and There is an effect that a uniform high quality film can be formed thereon.

In the thin film forming method of the present invention, an oxidizing gas excited by plasma is reacted with silanol having at least one hydroxyl group bonded to a silicon atom to deposit / form a SiO ₂ film on a substrate. As a result, there is an effect that interaction with the surface of the substrate is reduced, surface diffusion is promoted, and a high-quality SiO ₂ film having improved step coverage is obtained.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing the configuration of a thin film forming apparatus according to a first embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view showing the configuration of a thin film forming apparatus according to a second embodiment of the present invention.

FIG. 3 is a schematic cross-sectional view showing the configuration of a thin film forming apparatus according to a third embodiment of the present invention.

FIG. 4 is a partial plan view of a porous diffusion plate in the thin film forming apparatus of FIG.

5 is a partial cross-sectional view taken along the line AA ′ of FIG.

FIG. 6 is a schematic cross-sectional view showing the configuration of a thin film forming apparatus in Embodiment 4 of the present invention.

FIG. 7 is a schematic cross-sectional view showing the configuration of a thin film forming apparatus in Embodiment 5 of the present invention.

FIG. 8 is a schematic cross-sectional view showing the structure of a thin film forming apparatus in Embodiment 6 of the present invention.

FIG. 9 is a characteristic diagram showing the relationship between the film forming rate at the central portion and the peripheral portion of the substrate and the pressure in the reaction chamber in Example 6.

10 is a characteristic diagram showing the relationship between the film forming rate at the central portion and the peripheral portion of the substrate and the pressure inside the reaction chamber in Comparative Example 1. FIG.

FIG. 11 is a characteristic diagram showing the relationship between the film forming rate at the central portion and the peripheral portion of the substrate and the pressure in the reaction chamber in Comparative Example 2.

FIG. 12 is a schematic cross-sectional view showing an example of the configuration of a thin film forming apparatus used for carrying out Example 7.

FIG. 13 is a schematic cross-sectional view showing the structure of a conventional thin film forming apparatus in which window fogging is prevented by a grease application method.

FIG. 14 is a schematic cross-sectional view showing the structure of a conventional thin film forming apparatus in which fogging of a window is prevented by a gas purging method.

[Explanation of symbols]

 1 Reaction Chamber 2,32 Substrate 3,33 Support 4 Plasma Generation Chamber 5,35 Quartz Tube 6,36 Electrode 7 Non-Depositing Gas Introducing Tube 8 Raw Material Gas Introducing Tube 9,39 Exhaust Port 10 Illumination System 11 Light Introducing Window 12 , 15 Porous diffusion plate 13,43 Magnet 14 Purge chamber 16 Through hole 17 Jet hole 18,19 Light transmitting plate 20 Heater 21,31 Reaction vessel 22 First gas introduction pipe 23 Second gas introduction pipe 24 Third Gas introduction pipe 25,45 High frequency power supply 37 Oxidizing gas introduction pipe 38 Silanol gas introduction pipe

Claims (16)

[Claims] 1. A thin film forming apparatus for forming a thin film on a substrate, which comprises a reaction chamber, a support provided in the reaction chamber for holding the substrate, and a translucent porous diffuser plate between the reaction chamber. A plasma generating chamber which is provided adjacent to the substrate and at least partially made of a translucent member, plasma generating means for generating plasma in the plasma generating chamber, and first gas introducing means for introducing gas into the reaction chamber. Second gas introducing means for introducing gas into the plasma generating chamber, exhaust means for exhausting the reaction chamber and the plasma generating chamber, and the plasma generating chamber and the porous body provided outside the plasma generating chamber. A thin film forming apparatus comprising: a light source for irradiating a substrate held by the support through a diffusion plate with light, and at least a surface of the porous diffusion plate on the reaction chamber side is a diffusion surface for scattering light. 2. The thin film forming apparatus according to claim 1, wherein the plasma generating chamber has a cylindrical shape, the side wall is made of a quartz tube, and the porous diffusion plate is arranged on the bottom surface. 3. The thin film forming apparatus according to claim 1, wherein a large number of through holes having a diameter of 3 mm or less are formed in the porous diffusion plate so as to have an aperture ratio of 1 to 5%. 4. A thin film forming apparatus for forming a thin film on a substrate, comprising: a reaction chamber, a support provided in the reaction chamber for holding the substrate, and at least one surface of which is transparent. A porous diffusion plate that is a diffusion surface that scatters light and that is provided with a plurality of through holes; and a purge chamber that is provided adjacent to the reaction chamber through the porous diffusion plate and at least a part of which is a translucent member. A first gas introduction unit provided in the porous diffusion plate for introducing a deposition gas into the reaction chamber, and a second gas introduction unit introducing a non-deposition gas into the purge chamber;
Exhaust means for exhausting the reaction chamber and the purge chamber,
A thin film forming apparatus having a light source which is provided outside the purging chamber and irradiates light onto a substrate held by the support through the purging chamber and the porous diffusion plate. 5. A thin film forming apparatus for forming a thin film on a substrate, comprising: a reaction chamber, a support provided in the reaction chamber for holding the substrate, and at least one surface of which is transparent. Plasma generation that is a diffusion surface that scatters light and that is provided with a plurality of through holes, and a plasma diffusion member that is provided adjacent to the reaction chamber via the porous diffusion plate and at least a part of which is a translucent member Chamber, plasma generating means for generating plasma in the plasma generating chamber, first gas introducing means provided in the porous diffusion plate for introducing a depositing gas into the reaction chamber, and non-exposing to the plasma generating chamber. Second gas introducing means for introducing a deposition gas, exhaust means for exhausting the reaction chamber and the plasma generating chamber, and the plasma generating chamber and the porous diffusion plate provided outside the plasma generating chamber The thin film forming apparatus having a light source for irradiating light to the held substrate to the support. 6. The thin film forming apparatus according to claim 1, wherein the plasma generating means introduces high frequency or microwave power into the plasma generating chamber. 7. A thin film forming apparatus for forming a thin film on a substrate, comprising: a reaction chamber at least a part of which is a translucent member; a support provided in the reaction chamber for holding the substrate; First gas introducing means for introducing a deposition gas into the reaction chamber at a position corresponding to the central portion of the substrate, and the first gas introducing means is provided independently of the first gas introducing means and the peripheral portion of the substrate in the reaction chamber. Second gas introducing means for introducing the deposition gas to a position corresponding to, evacuation means for exhausting the reaction chamber, and light for a substrate provided outside the reaction chamber and held by the support. A thin film forming apparatus having a light source for irradiation. 8. A thin film forming apparatus for forming a thin film on a substrate, comprising a reaction chamber, a support provided in the reaction chamber for holding the substrate, and having a plurality of through holes which are transparent. A porous diffusion plate, a plasma generation chamber which is provided adjacent to the reaction chamber through the porous diffusion plate and at least a part of which is a translucent member, and plasma generation means for generating plasma in the plasma generation chamber. A first gas introducing means for introducing a deposition gas into a position corresponding to a central portion of the substrate in the reaction chamber; and a first gas introducing means provided independently of the first gas introducing means for the substrate in the reaction chamber. Second gas introducing means for introducing the deposition gas to a position corresponding to the peripheral portion, third gas introducing means for introducing the non-deposition gas into the plasma generation chamber, the reaction chamber and the plasma Exhaust to exhaust the generation chamber The thin film forming apparatus having a light source for illuminating the stage, the light in the plasma generation chamber disposed outside the plasma generation chamber and the perforated diffuser plate retained substrate to the support via the. 9. The thin film forming apparatus according to claim 8, wherein the plasma generating means introduces high frequency or microwave power into the plasma generating chamber. 10. The first gas introducing means comprises a transparent thin tube having a through hole in the wall surface.
The thin film forming apparatus as described in the item. 11. The thin film forming apparatus according to claim 10, wherein the first gas introducing means has a rectangular cross section. 12. A thin film forming method for forming a SiO ₂ film on a substrate, which comprises reacting an oxidizing gas excited by plasma with a silanol having at least one hydroxyl group bonded to a silicon atom, A thin film forming method having a reaction step of depositing a SiO ₂ film on a substrate. 13. The oxidizing gas is at least one gas selected from O ₂ , O ₃ and N ₂ O.
The thin film forming method described. 14. The method for forming a thin film according to claim 12, further comprising a step of reacting an organic silane with water to produce silanol used in the reaction step immediately before the reaction step. 15. The method for forming a thin film according to claim 12, further comprising a step of reacting an inorganic silane with water to generate silanol used in the reaction step immediately before the reaction step. 16. The method according to claim 12, wherein the substrate is irradiated with ultraviolet light or visible light during the reaction step.
The method for forming a thin film according to item.